The first period of this grant has focussed on the facile production of short lived nuclides with special view towards applicability in medical cyclotrons. In this regard a definitive excitation function for carbon-11 production via the N14 (p, alpha) C11 reaction has been determined and comparison with previously determined functions has been made. It is now possible to make precise calculations as to production capabilities in any nuclear medicine facility with access to a cyclotron capable of delivering protons. Tables for production as a function of bombardment energy were generated. Use of iodine-123, a nuclide whose widespread use would result in substantially lower patient doses over existing procedures utilizing iodine-131 depends again on production capability. While iodine-123 for thyroid scaaning is now commercially available, high yield methods for medical cyclotron use have not been detailed in the literature. The tellurium (p,xn) reactions have considerable promise. We have determined the excitation function for one of the most accessible, the Te124(p,2n)I123 reaction. Excitation functions from threshhold to 30 MeV for it and competing reactions were measured, yield curves generated and conditions for maximizing purity established. A simple recycle method for the highly enriched target material was perfected. A special water cooled target was also developed. Production rates of 50-150 mCi/hr/bombardment on the BNL cyclotron are now routine. Scale up to current capabilities of medium energy medical cyclotrons would project to Curie/hr production rates. New liver, gall bladder and bile duct function agents have been developed and have been tested in animal models. Thy are superior to currently used agens such as radioiodinated Rose Bengal and Bromosulfophthalein, in that liver uptake is high, clearance is rapid and theire is no significant kidney accumulation. These compounds are analogs of Indocyanine green, a compound used in medical practice today. The core compound is named 2-(7,3-dihydro3,3- dimethyl-1-(4-sulfobutyl)-H2-indol-2-ylidene)-1,3,5-heptatrienyl)-3,3- dimethyl-1-(4-n-slfobutyl)-H3-indolium hydroxide inner salt. Clearance rates can be mediated by halogen substitution at the 5' position. Studies on production methodsfor anhydrous fluorine-18 reagents via the Ne(d,alpha) F18 (Text Truncated - Exceeds Capacity)